Stance Control Knee Joints: Making a difference for long leg brace wearers.

There are currently 8 different knee joints that are on the market that fit the description of a stance control knee joint. These are joints that are designed to unlock during swing phase and remain locked during stance phase of gait.  The goal is to mimic normal biomechanics of the knee as closely as possible, while still supporting weak or absent muscles. Previously, when a patient was fit with a long leg brace, the clinician had the option of a free motion joint with posterior offset (so the knee joint hit an end point when the weight line of the body was anterior to the joint) or a locked knee (avoiding all motion.) In the case of the posterior offset knee joints, if above knee weakness is a concern the patient could loose stability while standing. On the other hand, a locked knee creates a poor gait pattern where circumduction (swinging your leg outward) is necessary to advance the limb. The stance control is an appropriate solution to this problem of mechanics, but selecting the correct one for the patient is critical.  Although the function of each joint is the same the mechanisms by which they work are very different. The clinical evaluation of the individual patient is what helps determine which knee joint is most appropriate and what other components may be necessary in the fabrication of the orthosis.

Indications:
• Isolated Quadriceps weakness or absence
• Unilateral leg paralysis
• Floor Reaction AFO wearers who need increased stability during stance
• Increased stability for posterior offset or free knee KAFO wearers
• Increased knee stability for Solid ankle and posterior stop AFO wearers




Contraindications:
• Weight limits per joint
• Significantly impaired cognition, balance, or motivation
• Knee flexion contraction
• Coronal position that is uncontrolled or overly significant